tests/test-fetch

Add core copy detection algorithm

This adds findcopies, which detects merge-relevant copies between
files in a pair of manifests back to the merge ancestor.

While the merge code invokes the copy detection routine, it does not
yet use the result.

#!/bin/sh

echo "[extensions]" >> $HGRCPATH
echo "fetch=" >> $HGRCPATH

hg init a
echo a > a/a
hg --cwd a commit -d '1 0' -Ama

hg clone a b
hg clone a c

echo b > a/b
hg --cwd a commit -d '2 0' -Amb
hg --cwd a parents -q

echo % should pull one change
hg --cwd b fetch ../a
hg --cwd b parents -q

echo c > c/c
hg --cwd c commit -d '3 0' -Amc
hg --cwd c fetch -d '4 0' -m 'automated merge' ../a
ls c